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Story of an Alternator partial failure

douglassmt

Well Known Member
Story of a partial Alternator failure

I'm posting this in the hopes that it might help someone else who encounters a similar problem. Here's the scenario:

RV-10, IO-540, ~250 hours, VP-X, AFS 5600/5500, GTN650, SL30, GTX327, Plane Power 60 amp primary, Plane Power 30 amp backup alternators.

On one recent flight, my 650 Comm circuit trips the electronic circuit breaker (ECB) on the VP-X. Hmm, that's never happened before. Reset in flight, no recurrence. Next flight, no problems. Next flight, same thing, only reset in flight doesn't work. Switch to SL30 comm, land, reset ECB on ground, stays on. Two flights later, GTX327 trips during runup. Reset, no problem. Then in flight, the 650 Comm trips, the 327 trips, and the flaps trip, not all at the same time. By this time (some might argue a little late), I'm getting concerned, the plane is grounded until I figure this out.

After discussions with Vertical Power (thanks Marc and crew), he suggests the most obvious solution is shorts between VP-X and the two devices that tripped. I'm a little skeptical because they all happened at once, the plane is nearly new, etc. However, I switched pins to the 650 comm circuit from the VP-X, tested it on the ground, it still tripped, which indicated the problem was not in the VP-X. I pulled and traced the wires between the VP-X and both units - good as new, no apparent chafing/cuts. I tested the 650 and 327 circuits with the boxes removed from the trays - no circuit breaker trips and no amperage draw at all.

What I learned at this point was that the VP-X gives a reason for the trips - either short circuit, overcurrent, or current fault (this last has to be enabled for each device). I should have looked at the reason for each trip initially but I did not. When I retested, all the trips were listed as short circuits. OK, so I've now eliminated shorts in the wires, shorts in the connectors at the back of each box, and probably the VP-X. Marc offers to look at my VP-X anyway so I send it in. They look it over but cannot find anything. They send me a NEW unit anyway! So what could be the matter? The alternator must be working fine or my battery would be dead, right?

By this time I'm getting frustrated. I repeat the runup (when the 327 now trips every time) while monitoring the amps for the problem circuits. Well now, at idle, the two circuits are drawing 0.4-0.7 amps, but it wavers a little. At about 1400 rpm, the amps go crazy, bouncing from 0.4 to 13 to 30 to 22 to .5, until eventually the 327 trips (ECB set at 3 amps). Same thing on the 650 comm circuit but it does not always trip - odd, because the ECB is set at 10 amps. The total amps drawn (as reported on the VP-X page) bounces around in the same way. However, the current produced by the alternator (Hall effect sensor) is steady. I decide to check other circuits and notice that the amps on the autopilot (AFS) and the SL30 comm are also bouncing around at runup RPMs, although neither ever tripped. The flaps ECB never tripped again, but I never flew again until the problem was resolved.

Then I repeat the runup on the backup alternator. Nothing, no trips, no amps fluctuation, no nothing. Works perfect.

Ok, now we're getting somewhere. I start to focus on the main alternator. I call Plane Power and talk to Dick, who is very helpful. He gives me some ideas for troubleshooting the alternator: supply the field voltage direct from the battery instead of through the VP-X (did not solve the problem), check for loose connections (none), watch for voltage fluctuations (aha!). At this point, I notice that the VP-X page is reporting a voltage that is below 13V when on the main alternator. I'm not sure how long this has been happening, but that is now a clear indication something is amiss.

Now I am strongly considering sending the alternator in to Plane Power for them to look over (they offered) when my hangar neighbor offered to let me swap out his exact same model alternator for mine and see if it fixes the problem. After 15 minutes the alternators are swapped and the problem has gone away. That's all I needed to know. The alternator is going in. I also noticed that the windings on my alternator were discolored in places. When I mentioned that to Plane Power, he said that is a sure sign of a broken stator wire.

Plane Power looks it over the next day, finds two broken stator wires, repairs it under warranty, returns it the third day. After installation and ground testing, flight testing shows problem resolved.

So here is what I learned...

1. The vendors in the experimental world are great - special thanks to Vertical Power and Plane Power; and to Christer @ Steinair and Bob @ TCW for some valuable help. Vertical Power did things for me they didn't have to do.
2. Alternators don't always fail outright and completely. Mine was apparently making enough power initially to supply the plane and recharge the battery but was making so much noise that the VP-X sensitive ECBs interpreted it as amperage swings and tripped several ECBs. It did apparently progress to nearly complete failure eventually, which made the diagnosis easier. My alternator worked fine at idle but not at higher rpm even at the end.
3. I should have kept a better eye on the power system fundamentals: alternator voltage should be 14.5+ and the amps reported by the VP-X should not swing wildly, check the reason for any circuit breaker trips.
4. Alternator windings shouldn't be discolored - another good thing to check at every oil change. I have no idea how long my stator wires were broken.
5. I have hangar neighbors who are great folks, willing to pull their cowl, remove their alternator, and let me try it.
6. There's a tendency to question everything about your system when these - apparently intermittent - electrical problems occur. Troubleshooting should start with the basics, eliminate possibilities until you find the problem. Don't panic, just logically work through the options and don't be afraid to get help from experts.
7. In the end, my system worked as it was intended. The VP-X protected the wires and devices and provided lots of valuable information that would have helped me find the problem sooner if I had known how to read and interpret it...hence the reason for this post.

Hope this helps someone else who might run into a similar problem.

PS - Plane Power suggested that the cause might be an out-of-balance prop. I was planning to have the prop balanced anyway - and will - but I strongly doubt that such could have caused the damage to the alternator. The engine and prop seems to be pretty darn smooth.
 
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Glad you got everything resolved!

Agree with the support from VP and Plane Power. Christer on the other hand. (just kidding) Actually, Christer is just about the only one from SteinAir that still comes to visit the RV10 HQ at Scholler since Stein started staying the house. So I guess he gets an "attaboy" for giving us RV-10 guys a little extra TLC.
 
Just as a point of reference. I know of several Plane Power alternator failures, not just from reading here but from RVers I know. This one failed at 250 hours. The 120A Bosch alternator in my VW diesel just failed at 254K mi a couple of days ago. Using 60mph as an average speed, that comes in as 4233 hours. I bought a rebuild for $90, no core charge. Had that alternator failed on a trip somewhere without a neighbor to help you, you would have been stuck for a few days. I just fail to see the logic in buying something that is of "aviation" quality when in reality its not, and its a heck of a lot less convenient to run down to the nearest Napa or Autozone to get a replacement.
 
New to me

Just as a point of reference. I know of several Plane Power alternator failures, not just from reading here but from RVers I know. This one failed at 250 hours. The 120A Bosch alternator in my VW diesel just failed at 254K mi a couple of days ago. Using 60mph as an average speed, that comes in as 4233 hours. I bought a rebuild for $90, no core charge. Had that alternator failed on a trip somewhere without a neighbor to help you, you would have been stuck for a few days. I just fail to see the logic in buying something that is of "aviation" quality when in reality its not, and its a heck of a lot less convenient to run down to the nearest Napa or Autozone to get a replacement.

Thanks for the input. I'm new to this plane ownership and of course this is my first build, so I went with the recommendations of the engine builder - Aerosport Power. The primary alternator came with the engine. As I get more comfortable with the "experiment" part of experimental, I might be willing to try new things. Also, that's why I have a substantial backup alternator - so I can continue on somewhere if my primary fails or acts up.
 
Just as a point of reference. I know of several Plane Power alternator failures, not just from reading here but from RVers I know. This one failed at 250 hours. The 120A Bosch alternator in my VW diesel just failed at 254K mi a couple of days ago. Using 60mph as an average speed, that comes in as 4233 hours. I bought a rebuild for $90, no core charge. Had that alternator failed on a trip somewhere without a neighbor to help you, you would have been stuck for a few days. I just fail to see the logic in buying something that is of "aviation" quality when in reality its not, and its a heck of a lot less convenient to run down to the nearest Napa or Autozone to get a replacement.

Commonly excepted logic (it does make sense), but I belive it to be faulty.
It is highly likely that if you put that Bosch alternator on a 4 cyl Lycoming, it wouldn't have lasted for nearly as long. The operating conditions on an airplane are usually quite different than they are on modern cars or trucks.

Not saying that lower cost auto alternators are not a good option for our airplanes, just saying that it shouldn't be assumed they would last the same # of hrs.
 
From my experience only... B&C has the best track record on alternators.

Also curious why you didn't have a voltage alarm or notice that the voltage was lower than "normal"?
 
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Like Bryan, my first airplane, first(hopefully last) build and went with what Van's recommended. We have two batteries 925/680 with enough power to complete a 4.5 hr flight if needed. We can recharge overnight and return home the next day to repair too. We also set low voltage warning slightly below the normal 14.2-14.3.

Bryan, Do you have the cooling blast tube on alternator? What about metal shield protection from #1 exhaust pipe? I don't have either but have measured 300F degrees surface temps on side of alternator facing exhaust pipe. No telling what internal temps are running. Wish I had an embedded thermistor sensor. No, my truck alternator does not run that hot!
 
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Commonly excepted logic (it does make sense), but I belive it to be faulty.
It is highly likely that if you put that Bosch alternator on a 4 cyl Lycoming, it wouldn't have lasted for nearly as long. The operating conditions on an airplane are usually quite different than they are on modern cars or trucks.

Not saying that lower cost auto alternators are not a good option for our airplanes, just saying that it shouldn't be assumed they would last the same # of hrs.

They won't last as long because they spin at a higher RPM in an aircraft due to the ring gear size, and this is why I prefer the smaller diameter pulley.

A casting is a casting, a pulley is a pulley, a stator is a stator, brushes are brushes, and they're not putting ABEC7 bearings in the things. An "aviation" alternator implies some sort of gold plating to a lot of people building RVs nowadays. They're not really any better.

Once I rebuilt a B&C starter. It required new brushes. B&C wanted a $130 for the brush assembly. Ummm, no thanks. I went and visited a friend who has a starter and alternator shop and got the same exact parts for $5.00. The B&C starter uses a Hitachi motor. But if you call them and ask they will tell you they have them custom built out of materials such as unobtanium coated with impervium.
 
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Excessive heat, large temperature swings, vibration, moisture all affect them more in a plane. Possibly no better quality. When I called Plane Power and spoke to Dick to ask a few questions, it made it worthwhile paying 4X as much. Try calling your car alternator manufacturer and ask for troubleshooting advice. At least I know most of my money is going to support American jobs and businesses, which means more to me.
 
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Like Bryan, my first airplane, first(hopefully last) build and went with what Van's recommended. We have two batteries 925/680 with enough power to complete a 4.5 hr flight if needed. We can recharge overnight and return home the next day to repair too. We also set low voltage warning slightly below the normal 14.2-14.3.

Bryan, Do you have the cooling blast tube on alternator? What about metal shield protection from #1 exhaust pipe? I don't have either but have measured 300F degrees surface temps on side of alternator facing exhaust pipe. No telling what internal temps are running. Wish I had an embedded thermistor sensor. No, my truck alternator does not run that hot!

I have neither on mine. I asked Dick about temps and he said it's unlikely to be a problem. They are rated/tested to 300F and it might only be a concern if I'm running at max amps capacity of the alternator (I'm not) in a very hot climate (negative). It is interesting you got 300F on the side of the alternator, so that might be something to think about.
 
Yes and no

From my experience only... B&C has the best track record on alternators.

Also curious why you didn't have a voltage alarm or notice that the voltage was lower than "normal"?

Walt -

Part of the anatomy of this failure is that it appeared to be gradual, initially intermittent, and was always partial. The other part is that the knowledge/experience/aptitude of the operator was also intermittent/partial :) I did not have my voltage alarms turned on (do now) and did not notice the voltage being low until very late in the process. I'm pretty sure they were fine initially, but again I certainly wasn't as attuned to that as I am now. The reason for the post was mainly the second part - those of us who aren't expert in matters electronique can learn from each others mistakes.
 
Ahh... but you don't have to be an expert to "Listen" to your machine :D

We should all know what "normal" is for our aiplane, normal sounds, engine indications, control feel, etc. are critical, so when something changes we should take notice and look into why before we go flying again.

Your initial post with multiple popping CB's/resetting/go flying and then repeating this exercise multiple times, with hopefully different results, could have been a recipe for disaster.

This is exactly what the NTSB report is all about :eek:

When something is wrong your machine it will inevitably try to let you know, the question is:
1) are you listening
2) do you choose to ignore

Please realize that I am not trying to be critical of you or your abilities, I just want folks to be safe out there!
 
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No offense taken, Walt. I deserve some of it, maybe all. And the discussion is healthy.

The popping CBs were intermittent at first, and the reset worked in most cases. They didn't happen every flight, maybe every third flight. Only when it became a "cascade" and the CB wouldn't reset did I stop and troubleshoot. Also, on the VP-X, the CBs are adjustable, so "nuisance" trips can occur if you've got the CB value set too low. I've also heard from others of CBs tripping for no apparent reason - occasionally. So, while I was probably patient with this for too long, I wasn't completely oblivious.
 
I'm still curious as to why exactly the VP-X ECB's tripped. Did the voltage fluctuations caused by the faulty alternator somehow cause actual over-current events on those load circuits, which the VP-X correctly detected and handled? Or is the VP-X itself somehow susceptible to voltage fluctuations, and as a result, erroneously detected over-current events on those load circuits when really there were none?

Perhaps Marc Ausman could chime in?
 
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"By this time I'm getting frustrated. I repeat the runup (when the 327 now trips every time) while monitoring the amps for the problem circuits. Well now, at idle, the two circuits are drawing 0.4-0.7 amps, but it wavers a little. At about 1400 rpm, the amps go crazy, bouncing from 0.4 to 13 to 30 to 22 to .5, until eventually the 327 trips (ECB set at 3 amps)."

Obviously the units cannot draw the amp readings above, so the voltage fluctuations to the VPX must be causing the erroneous amperage readings in the VPX somehow.
 
ALT

In reguards to post #3 I think you can run down to local parts and get same Alt looks like my suzuki samurai
 
Don't know

i'm alittle curious: What caused the stator windings to break at 250 hours?
Tom

That's a good question. Bottom line, I don't know. The alternator came with the engine from Aerosport Power, no trauma of any kind since it's been in my hands, never even been off the engine. I suppose it's possible that it got bumped in shipping somewhere, but that's very unlikely. Dick at Plane Power suggested that they most often see this failure in planes with heavy vibration, i.e., unbalanced prop or the like. I think my engine/prop run very smooth, so I have serious doubts about that being the cause. I have scheduled a prop balancing anyway because I was planning to do it before this happened. The only other thing I can think of is that the IO-540s that I've flown in (mine and the factory plane 410RV) both shudder significantly on shut down. When I asked Mike Seager about it, I recall that he shrugged and said all the 540s do it. Still, even that type of vibration shouldn't - in my opinion - cause stator wires to break. If I learn anything else from the prop balancing or the future of the rebuilt alternator, I'll certainly post. I'm curious too.
 
Vibration/resonance can cause stator winding failures as well as excessive heat.
All of those insulated wires must be held very secure, but there will still be movement due to thermal changes. A brand new engine/prop vibration analysis will typically indicate 0.4-0.8 IPS. We may not think 0.5 IPS is bad until you have flown one at 0.1 IPS. After balancing, you should see 0.1 IPS or less. Let us know what your vibration levels are.
 
I can't say exactly what the issue was since everything worked fine here in the shop. My guess is that the voltage fluctuations caused the current to fluctuate. Once the current fluctuated outside the specified limits (both time and amount) then it tripped as it should. When the current fluctuations are extremely high then it detects that as a short circuit, which is what must have happened, IMO.
 
Very Helpful

This post really helped me. I have almost the identical problem. You save me a lot of time! Thanks, Doug
 
Prop was fine

Good, glad it helped you. By the way, I had my prop balanced a few weeks ago. Before he touched it, it was at 0.099, just under what they like to see as a goal. He added one bolt at the prescribed location and it went to 0.028, so the prop was not out of balance.
 
This post really helped me. I have almost the identical problem. You save me a lot of time! Thanks, Doug

Welcome David! I love to see a first post where someone has already donated. As you've learned already, this community is the best value in all of aviation.

Also: I worked with Bryan on his problem for several hours, including running the VP-X through its paces trying to isolate the problem. He's right that these kinds of intermittent problems can be frustrating to diagnose. In his summary, he emphasizes all the symptoms that ended up being relevent to the actual problem, but remember that's only apparent after the true cause is found; Bryan didn't mention the many other "symptoms" which distract you when you don't yet know what is important and what's not. He did a great job of noting everything that might be at issue, so his summary here does a disservice to his troubleshooting ability.

--
Stephen
 
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Thank Stephen,

VAF is is a wonderful resource.

I pulled the alternator today and I will have it bench tested. There were no obvious issues. No loose wires, good connections. The alternator looks good to the eye. Not sure what else to do but bench test it.... so I removed it. Any thoughts the best ay to test? Also, if it needs replaced, what is the best quality unit to buy and where can I get it? Its flying season and I want to be up:))
 
Thank Stephen,

VAF is is a wonderful resource.

I pulled the alternator today and I will have it bench tested. There were no obvious issues. No loose wires, good connections. The alternator looks good to the eye. Not sure what else to do but bench test it.... so I removed it. Any thoughts the best ay to test? Also, if it needs replaced, what is the best quality unit to buy and where can I get it? Its flying season and I want to be up:))
Find yourself a good old fashioned auto electric shop that rebuilds alternators. I took my 400 hour 60 Amp Plane Power alternator to one and they replaced the stator winding; because of three broken leads. This was two days before leaving for Florida this past January. I have the plane down for it's Conditional now and will be replacing the Plane Power with the automotive model flown by all of the Team AeroDynamics guys. The automotive one probably isn't any better or worse than the Plane Power but when they go out I can at least find one at the local O'Rileys or Auto Zone.
 
This post triggered my memory inflight

Flying today on three one hour legs. On second leg right over Class B Seattle our Transponder trips on VPX..Easy reset and continue on flight. 20 min later on final approach to land it trips again..thought it very odd but was on final so landed. Tested on ground and all seemed ok. Thought maybe power down had reset the problem maybe...during run up all seemed good and all engine instruments in green. On takeoff the transponder trips again...this time I saw erratic amp reading briefly. Stabilized from takeoff and reset transponder...then saw alt amps drop to zero...Bryans post came to memory and I switched to backup alternator. Amperage stabilized and transponder remained on in last hour leg. What you think I have a bad main alternator? But the point is Bryan posted this info helped me inflight to overcome the issue with no stress. Thanks for VAF and Bryan! who would of thought a transponder trip would indicate a failing alternator?
 
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Flying today on three one hour legs. On second leg right over Class B Seattle our Transponder trips on VPX..Easy reset and continue on flight. 20 min later on final approach to land it trips again..thought it very odd but was on final so landed. Tested on ground and all seemed ok. Thought maybe power down had reset the problem maybe...during run up all seemed good and all engine instruments in green. On takeoff the transponder trips again...this time I saw erratic amp reading briefly. Stabilized from takeoff and reset transponder...then saw alt amps drop to zero...Bryans post came to memory and I switched to backup alternator. Amperage stabilized and transponder remained on in last hour leg. What you think I have a bad main alternator? But the point is Bryan posted this info helped me inflight to overcome the issue with no stress. Thanks for VAF and Bryan! who would of thought a transponder trip would indicate a failing alternator?

The main alternator would be a good place to start. If it is a PP, then check the plug, the are failure points, as are broken stator wires. The plug is hard to check, so see DanH's "Fooled me" thread. If that is good, then I would remove the alternator and take it to an alternator shop (I would take it apart my self actually) and check to see if all three phases are working. That takes an oscilloscope. You might be able to measure the AC content, but if that means nothing, take it to the shop.

Thinking to Self - My brand new PP is beginning to worry me now with all these early hour issues. Lets see - OTS - $100, PP - $500 - B&C - $1000. Hmmmm. Add OVP and $100 is looking better all the time. Just replace every 200 hrs and golden. Or have a spare and dissemble and refurbish every 200 hrs and swap. Wonder what it costs to have the rotor balanced?? back to work.

Edit: The B&C web site had an error - the 60A alternator is not ~$1000 - - it is $530 plus $175 external regulator. (voltage adjustable and with OVP). I see a possible B&C in my future.
 
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Just to set the facts straight:
The new B&C 60 amp BC460-H is $530 and the reg is $175 = $705
The 40 amp unit (which is what I use) is $379 + $175 = $554

Other than a little extra work to install the regulator it seems like a no brainer to me :D
 
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Hybrid Approach

It's not difficult at all to take an off-the-shelf auto parts store alternator (just about any 60A Nippondenso will do, my particular preference is a Lester 14757 for a 1985 Civic), change out the pulley and swap the regulator for a terminal block, and then purchase a high-quality B&C regulator with over-voltage protection to drive it. Mine works great!
 
Just to set the facts straight:
The new B&C 60 amp BC460-H is $530 and the reg is $175 = $705
The 40 amp unit (which is what I use) is $379 + $175 = $554

Other than a little extra work to install the regulator it seems like a no brainer to me :D

Yeah - facts - - just to be clear, here is the check out basket and it is for one alternator - so either the website is wrong or something else, but the number I posted was not arbitrary.

Well, I called B&C and it is indeed $530, in spite of the screen capture below. We discussed the shopping cart price and he will have the web guys address that. But it gets better - they have a sale on this alternator bundled with the regulator for $595 right now. $110 off individual prices. So, apparently I am not an idiot (at least this time).

Edit: The B&C guy just called me back to thank me for finding the glitch - the special is about to end but will be back soon. Also for you EarthX people, the external regulator is adjustable and perfect for the LiFePo4 batteries! - - Yes, Walt - it is truly a NO BRAINER -

Screen%252520Shot%2525202015-09-25%252520at%2525203.25.11%252520PM.png
 
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in reply to the PP alternator issue

As I already posted in another thread related to PlanePower alternator failures, my PP alternator also failed at 250 hrs after some intermittent on/off behaviour during a short flight.
The cause was broken stator wires, exactly as reported by many others here.
Although the Hartzell people always tell you it's because of some vibration or misalignment issue, IMHO there may be a contributing factor in the way the alternator is designed. The stator wires are short, rigid solid-copper wires that go from the stator windings (where they are epoxied/waxed together with the rest of the winding) to the contacts, where they are secured with screws. Short and rigid + vibration = early failure.
I agree with RocketBob that after receiving dozens of reports of broken wires, the Company "aviation specialists" could have replaced them with either braided copper or built some tension relief to mitigate the problem. Especially when we pay north of 500$ for a part that has no improved durability compared to a 80$ stock car alternator.
 
in reply to the PP alternator issue

Also had a PP alternator failure w/remote regulator( @20 hrs ) on rebuilt O360.
I believe this may have been my fault though. I put an incorrect service loop on the #6 output wire stud that caused the nut to come loose (plus very low PP torque value). A bad service loop design(me). Flying along, service loop vibrated, loosened the nut creating a noise in the headphones that sounded like WWII submarine pings of the sonar. About two hours later .. Where is this noise coming from? Then zero amps....Now I know! The 35amp arcing caused the noise, nut melted off from heat. Cost about $200 by PP with shipping two ways. So far all is good now at 100hrs.

John
 
Mounts

And just to add to the discussion, alternator mounts should also be considered.

All below are for older "Case Mount" alternators.

A comparison of the thickness of the Lycoming part (top) and Vans part -

alternator-mounts_zpsmzekhcqd.jpg


The mount provided with the B&C alternator -

B-C%20alternator%20mount_zpsmn7eooqr.jpg
 
Bryan,

Thanks for the detailed writeup. I'm starting to have a VERY similar issue to the one you had, and my electrical system is pretty much the same (PP60, VPX, etc)

This gives me a huge head start in the troubleshooting process!

Ed
 
I have a recent thread rg my alternator failure.

I had the standard (at that time) alternator from Vans, which is a 60 Amp unit, internally regulated, no overvoltage protection....more or less an automotive alternator you can purchase for $90.

My failed HIGH in flight two weeks ago. The voltage went off scale high. It took me a little less than a minute to notice it.

By that time I had burned out one comm, my light speed ignition, and my autopilot.

And I was smelling smoke.

An emergency landing ensued.

So, at least yours failed low....

Mine is replaced now, with a Plane Power alternator and a loaner Plasma 3 box from Light Speed (thank you Klaus).

I am retrieving it on Saturday.
 
Here's another - kind of

I'm not flying yet. Very close, but not yet.

Not the same alternator issue but I just dealt with SB632 and was putting everything back together on my RV10 when I noticed a wire sticking out of my PP60 connector (field wire). I then literally just touched the connector and the other wires just fall out. I'm talking about the connector that ships with the wires already attached. I pulled the connector off and I can see that the wires are not crimped properly. It looks like they were crimped with the wrong size crimper.

Prior to all this the engine has run for about 40 minutes total so far and I've seen no indications of any alternator issues. I would have flown and there is no doubt I would have had an alternator failure on my first flight had I not been delayed by SB632.

I've been searching the forums and can't find what I'm looking for. I remember reading about alternator connector issues. Anybody remember where those threads are? Does anybody know the part number for this connector and/or the pins and pin extractor?
 
I'm not flying yet. Very close, but not yet.

Not the same alternator issue but I just dealt with SB632 and was putting everything back together on my RV10 when I noticed a wire sticking out of my PP60 connector (field wire). I then literally just touched the connector and the other wires just fall out. I'm talking about the connector that ships with the wires already attached. I pulled the connector off and I can see that the wires are not crimped properly. It looks like they were crimped with the wrong size crimper.

Prior to all this the engine has run for about 40 minutes total so far and I've seen no indications of any alternator issues. I would have flown and there is no doubt I would have had an alternator failure on my first flight had I not been delayed by SB632.

I've been searching the forums and can't find what I'm looking for. I remember reading about alternator connector issues. Anybody remember where those threads are? Does anybody know the part number for this connector and/or the pins and pin extractor?

Here you go - http://www.vansairforce.com/community/showpost.php?p=1098783&postcount=45 Cut/paste below - go to driftmotion.com

These terminals are squarish and need a narrow flat blade for a pin release. I just make one from .040" aluminum stock. Push and pull on the pin until it comes out. Pretty easy. I got a good supply of terminal pins. Get the seals too, as they provide strain relief and are needed with that stiff tefzel wire.

"Plane Power 60A Alternator

Rectifier: INR737 $39.95
Regulator IN257 ? $49.95
Bearing: 61014 ???
(alternatorparts.com)

Mating Connector: DM2085 $6.99
Pins: DM3284 $0.69
Seals: DM1598 $0.50
(driftmotion.com)"
__________________
Mike W
Venice, FL
 
Bryan's post has saved a few of us a ton of diagnostic time....but Bryan is intelligent and methodical so he gets the credit.
We are on our third plane power alternator in 500 hrs with all the same symptom at failure, transponder trips cb and ripple noise in intercom. Last one I sent in for repair was denied warranty as they said no issues found. They blame it on vibration, our prop has been balanced, any thoughts on cause of this?
 
Well, I've determined my problem IS being caused by the PlanePower 60amp. I've pulled it off the plane, and am shipping it to Hartzell to see if it will be covered under warranty.

Here's to hoping!
 
Puzzling

For some reason my email notices of replies to this thread went to spam, which I just noticed. Since my original PP failure at 250 hours TT (I think), I have had no issues. I check it carefully for black windings, loose leads, and other issues at every oil change, and I recently passed 1000 hours TT on the plane. My backup PP alternator continues to work fine when I check it periodically but I have yet to use it for a longer flight. Perhaps I should.

I'm not sure why Jack's alternator would be failing the same way so many times. One thing I did was put a max temp recording sticker on my main and backup alternators. I can't recall the temps right now but I don't believe they were anywhere near 300F on either of them. My original issue happened when PP was still independently owned. I've had a little correspondence with Hartzell since they bought PP and they seem good to work with but I would like to know how they handle warranties.

One side note, I've had the metal shroud on my backup PP FS1 alternator break twice now. The first time they scrounged up a replacement and sent it no charge. The second time they told me I could buy one on Aircraft Spruce but I haven't been able to find it. The real answer is they need to make them stronger.
 
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Regarding the shroud, Hartzell recommended to us, using some RTV on the weak places of the shroud when replacing it. That has worked for me and actually looks like a very good idea. I think in retrospect that I would do that on a new alternator from the get go?
 
Where to buy

Did you find where to buy the replacement shroud? Seems like they could make it out of a better metal - the stuff feels pretty cheap.
 
At the time of ours failing Hartzell supplied us with one that was laying on a desk. My suggestion is to call Hartzell for a part number so when they direct you to ACS, ACS will be able to find it in their system? I had to do this early on for a PP brush set part number for ACS to ID the part.
 
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